US2642850A - Heating plant - Google Patents

Description

June 23, 1953 R. w. DE LANcEY HEATING PLANT Filed Feb. 9, 1950 ATTORN EY June 23, 1953 R. w. pEL-ANcEY HEATING PLANT 2. 'Sheets-Sheet 2` Filed Feb. 9. 1950 'lNvEN-roR /44 ELM/fn ATTORNY Patented June 23, 1953 n HEATING PLANT Ralph. W. De Lancey, Meriden, Conn., assigner to The Miller Company, Meriden, poration of Connecticut s Conn., a. cor,

Application `'la'ebruary 9, 195o, serial No. 143,291.

The present invention relates to heating plants. The present invention contemplates an oil fired furnace or heating plant of the type employing a boiler and used either for steam or hot water heating, or for supplying domestic hot Water.

According to the present invention the heating plant uses a boiler yoi' muchsmaller dimension and water capacity than is customarily found in steam or hot water boilers used for similar output, and according to the present invention the heating capacity of the boiler is equivalent to the heating capacity vof conventional boilers oi much greater weight, size,y and water capacity.

According to the present invention the oil burner, preferably of the vaporizing type, is operated at pressure above atmospheric, the com'- bustion chamber of the boiler is small, and the pressure in the combustion chamber of the boiler when operating 4at high re is also above atmospheric.

The present invention contemplates that the hot gases at positive pressure i; e. above atmospheric pressure, shall not lescape past the breeching to the chimney until the temperature has been reduced to abstract from them as much heat as economically possible. Accordingly the hot gases are compelled to pass through vertical re tubes each of which contains a spiral baille provided for the purpose of compelling the gases to revolve as they rise. This operationslows the vertical movement of the gases, compels them to revolve in the flues so that they hug the nre tube walls and give up their heat energy. The vertical height of `the combustion chamber is, according to the present invention, selected so Claims. (Cl. 122-458) that the iiame from the burner will ll the en- Y tire combustion chamber and lso that flame can play upon the spiral baffles heating them to redness with `excess air present thereby preventing' the formation of soot or carbon. Thebaiiles initiate the helical movement of the gases which continues after the gases pass above the bailles,

the pitch of the helix shortening as the cooler eration; LFigure 2 is a sectional view takenon the line y2 2 of Fig-ure 1;

n Figure `1 is a verticalsectional view through one form of heating plant arrangedior steam op- .Figure' 3'is a' vertical sectionalv view through a'modiiled form of boiler; and f s ti Figure 4 is a topplan view with parts in sec- I'he structure shown in Figures 1 and 2 is provided with four legs I0 (pieces of pipe) for purposes of supporting'the boiler itself above the iioor. The boiler structure proper includesa square'base II, an outer cylindrical wall I 2,-an

inner shorter cylindrical-wall I3, a lower plate or crown vsheet I4 and an upper plate or crown sheet I5. The plates Il and I5 are, as shown in Figures 1 and 2-,apertured to receive four tubes IB preferably cut from lengths of boiler tubing. The cylindrical shells or walls i2 and I3 are apertured to receive a tube Il for a door openp ing. The upper plate I5 is provided with a cen'- tral bushing I8 for van outlet pipe and Aan off center bushing I9 for a safety valve. The outer shell I2 of the boiler is provided kwith a bushing 20 near the bottom for the return,- and bushings ZI, 22 Lbelow the water line for domestic hot water heater and aquastat, respectively, and a bushing 23 for a low water cut-out. yThe outer shell is also provided with bushings indicated at 24 for gauge connections. The bottom or base II is provided withv a central aperture 25.

The base, the inner and outer shells and upper and lower plates or crown sheets together with the tubes I6 'and vII and the bushings I8 to 24, f

inclusive, are formed into a single unit by welding.. The opening 25 in the base I I is provided to receive the burner 26, this burner being preierably in the form of a vaporizing or pot type burner fed by oil through an inlet pipe 21 connected with constant level valve 28 and supplied with air under pressure by a blower unit 29 and conduit 30.

Vertical ktubes I6, I6 receive spiral `b'aiiles 3I.-

These bailies' may be made of cast iron or other Asuitable meta-l, or ceramic material, and are preferably somewhat more than one turn in length and are locatedin `the lower part of the tube so that theupper part of the tube is free. The bailles may be supported by rU-shaped yokes 32.

The opening Ilis closed by a door33 tight enough to resist internal pressure and provided with a sight opening 33'. The water inlet, which may be the return line,is indicated at 3l, the steam or hotwater outlet line is indicated at 35.

A trombone type domestic hot water heater is indicated at 36, an aquastat at 31, a low water cut-out at 38 'and a safety valve at 39. The outer shell I2 extends upwardly above the upper sheet I to form a breeching 40, and is covered by a plate 4I. A pipe 42 extends laterally from the side of the smoke box and connects with the pipe 43 which leads to the chimney. The gauge glass is indicated at M.

It will, of course, be understood that when the boiler is intended for hot water heating or fory domestic hot water only it may be provided with the usual connections.

Vaporizing burners using a blower whereby positive pressures may be maintained are available in sizes to consume a gallon of fuel oil per hour. One gallon per hour of fuel oil equals 140,000 B. t. u. and at 80% efficiency 112,000 B. t. u. are available per hour. The corresponding boiler rating is 466 sq. ft. boiler steam radiation. Making the usual A. S. H. V.E. allowances for piping tax, pick-up and domestic hot water, the net rating of a boiler with 466 sq. ft. steam radiation is 298 sq. ft. of steam radiation. Such fuel consumption (1 gal. per hr.) is therefore adequate for heating the small house having an installation of 280 sq. ft. of steam radiation (or 450 sq. ft. of hot water radiation).

The boiler of the present invention is more especially designed for use with a burner of this output. The cylinder I2 of a boiler such as illustrated in Figures l and 2 for these purposes may be 17%" in diameter and 20" high and the boiler has a fire box 14" in diameter and'lO high and four tubes 4" in diameter and 12 high. The door opening is a 6" tube. The heating surface of such a boiler is 9.1 sq. ft. The ratio of square feet of boiler rating to square feet of heating surface is so that in the present boiler the boiler rating in square feet of steam is 51 times the area of the heating surface.

Many manufacturers make boilers of conventional types of comparable output for steam and hot water heating. The average rating of 51 typical boilers made by 41 manufacturers and ranging from 390 to 550 sq. ft. steam radiation, is 462 sq. ft steam. The heating surface for such boilers ranges from 17.5 sq. ft to 45.8 sq. ft. with an average of 32.5 sq. ft. of heating surface. Thus it will be seen that the average boiler of comparable output has about four times the heating surface of the present boiler.

A boiler such as described herein and made of 1A steel (conformed to A. S. M. E. specifications) weights, with four 4 fire tubes approximately 240 lbs. `If M3 steel, which is adequate for all stresses to which it can be subjected, the weight is approximately 130 lbs., the boiler tubes being of standard thickness. Boilers of conventional type in the same capacity weigh upwards of 550 lbs. and sometimes weigh as much as 1000 lbs. It will thus be seen that the present boiler requires much less steel or iron in its construction and that it can be shipped and handled at much less cost, and it can be set up with much less labor. One man can handle the boiler with ease. Owing to the small size of the boiler, the high conductivity and long life of copper is economically available.

Furthermore by making the boiler so small it is possible to have a very small water capacity.

4 For example, the capacity of the boiler illustrated in Figures l and 2 designed for the operation above stated need contain only about 8.3 gallons of water when operated for steam. Owing to the small amount of water in the boiler it is possible to obtain steam very quickly or to obtain domestic hot water without the necessity of keeping a very large boiler continuously hot.

When the burner is operating at high fire the air for combustion is supplied under positive pressure of about five hundredths to one tenth of an inch of water (measured in the flame zone), and the oil is fed in from the constant level valve under a head of about 1A to 3/8 of an inch at a sufficient rate to maintain the desired combustion rate under these conditions. Flame is discharged from the burner structure out under the spreader, as indicated in the drawings, and completely lls the combustion chamber, impinges directly on the side walls, and top of the combustion chamber and on the lower faces of the baffles 3| before passing upwardly into the .tubes I6. The pressure in the combustion chamber itself remains above atmospheric so that no air leaks in as in natural draft installations. The ascending gases are compelled to revolve as they pass up along the spiral baffles. This revolving of the flame makes the flame wipe the inner surfaces of the tubes I6 so as to make a very effective transfer of heat. The spiral bailles preferably terminate a substantial distance below the top of the'tubes as it was found that better operation is obtained. The baflles become so hot as to remain entirely free of soot or carbon. The ascending gases owing to the centrifugal forces developed continued to whirl or spin about the axis IG and as the cooling has reduced the volume of the gas from what it was in the combustion chamber, .the gases travel in a much closer helix than they do when confined by the spiral baffles. This operation has the effect of slowing down the vertical rise of the gases so that more time is available for the transfer of heat from the gases to the water or steam.

Analyzing the operation of the boiler from the point of view of draft loss, which is usually measured in inches of v water, it is obvious that draft loss must occur from the region where the flame is discharged from under the flame spreader all the way to the stack. As the pressure is positive in the burner and in the fire-box and is negative (i. e. below atmospheric) at the breeching the entire draft loss or loss of pressure except for the small frictional loss in the tubes I6 above the ballles is caused by the baille-s. The pressure developed by the forced draft for the burner is therefore made sufficient to compensate for this loss and maintain positive pressure all the way to the baflies and over all or nearly all the entire length of the tubes. This pressure condition is unlike that ordinarily present in boilers. In general in oil fired equipment negative pressure exists all the way down to the top of the fire box and in solid fuel furnaces the negative pressure exists all the way through the grates.

As a result of the action described it is possible to expect regular operation with stack temperatures under 600 F., and with CO2 of about 11%, indicating an efliciency of approximately It will, of course, be understood that with burners of large or smaller outputs, the sizes of the parts may be altered to suit the new output.

The boiler 5I shown in Figures 3 and 4, is generally the same as the one above described in detail. The combustion chamber is higher, the

wall height being substantially equal to the diameter, and the fire tubes shorter. Seven fire tubes 52 are used. The heating surface is increased and the water capacity lowered. Here the spiral baffles 59 have one complete turn in the tubes and about a whole turn projects into the combustion chamber to facilitate heating the bales. The rods 54 which support the baffles also carry llers 55 which may take any convenient form, the purpose being to retard collapse of the spiral as the gases rise. The drawing shows the usual steam connections. Here the hot water heater 56 is outside the boiler structure as there is insufficient room in the boiler of the design of Figures 3 and 4.

The present application is a continuation in part of my application Serial`1\lo..438,235, iiled April 9, 1942, now abandoned.

Applicant claims a priorityvdate for the present application of all subject-matter in common with that of applicants co-pending earlier application, Ser. No. 438,235, iiled April 9, 1942, now abandoned.

It isobvious that the invention may be embodied in many forms and constructions within the scope of the claims, and I wish it to be understood that the particular forms shown are but a few of the many forms. Various modications and changes being possible, I do not otherwise limit myself in any way with respect thereto.

What is claimed is:

1. A high output, small dimensioned, compact oil red heating plant having a rating of the order of 466 square feet of boiler steam radiation, comprising a natural draft producing stack, a boiler of smaller dimension andwater capacity than the customary boiler of similar output and boiler content accounting for `the draft loss between the positive pressure conditions in the re box and the negative pressure conditions at Y the top of the boiler and a stack temperature of 4. A heating plant `such as claimed in claiinl,

wherein the boiler includes a base apertured to receive the top of the burner, inner and outer concentric rsheet metal shells welded to the base,

' the inner shell forming the fire box wall and havprovided with a i'lrebox also of smaller dimension to have smaller combustion space than the customary boiler of similar input so that the ratio of square feet of steam radiation rating for the boiler to the square feet of combustion chamber heating surface islsubstantially greater than in customary heating plants of similar output and of the order o-f 51, the fire box having vertical walls and an apertured crown sheet, vertical tubes extending upwardly from the crown sheet to traverse the water space of the boiler and through which products of combustion escape, spiral baffles occupying vthe lower portions only of the tubes immediately above the crown sheet to offer resistance to the passage of the products of combustion and facilitate the transfer of heat to the boiler content, a forced draft oil yburner immediately below the re box and of a draft and fuel capacity of lthe order of one gallon per hour which maintains the entire nre box under positive pressures of from about iive one-hundredths to about ten one-hundredths of an inch of water, and produces ame which impinges on the fire box walls and crown sheet and lower ends of the bailles toheat the batiies to temperatures at which deposit of soot thereon is prevented under the conditions of excess oxygen maintained by the forced draft insufcient to drive iiame beyond the baiiies and ame wherein the primary combustion of the fuel takes place throughout the fire box and about the lower part of the baliies and the transition to secondary combustion'takes place along the lbailles, the aerodynamic resistance` provided by the Ibaiiies and the transfer of heat to the ing a diameter of from about 70% to about-100% of its length and being substantially shorter than the outer shell, an upper cover plate welded to the outer shell, a lower cover plate welded to the inner shell and forming the crown sheet, the cover plates having aligned apertures, and the tubes are welded into the apertured plates. f

5. A heating plant such as claimed in claim 1,

wherein the boiler includes a base apertured to v i receive the top of the burner, inner and outer con-v f Y centric sheet metal shells welded to the base, the

inner shell forming the nre box wall and having a diameter of from about 70% to about 100% of its length and being substantially shorter than.A the outer shell, a normally closed inspection door-opening in the form of a tube extending between both shells and welded thereto, an upper n cover plate welded to the outer shell, and a lower cover plate welded to the inner shell and forming the crown sheet, the cover plates having aligned apertures, and wherein the tubes are welded into the apertured plates.

RALPH W. DE LANCEY.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date y172,302 Dean Dec. 18, l1876 503,834 Doll Aug.' 22, 1893 517,745 `vGreen Apr. 3, 1894 525,932 Whitney Sept. 11,1894 660,761 Seyfarth Oct. 30, 1900 715,638 Cary Dec. 9, 1902 799,120 Way Sept. 12, 1905 1,184,936 Falkenwalde May 30, 1916 1,613,615 Lippert Jan. 11, 1927V 1,700,269 Loepsinger Jan. 29, 1929 1,745,204 Bowen Jan. 28, 1930 1,918,935 Sellers July 18, 1933 1,986,561 yDavis Jan. 1,1935v 2,063,261 Mees Dec. 8, 1936 2,064,080 Powers Dec. 15, .1936' 2,068,441 Valjean Jan.- 19, 1937 2,162,572 Bock June 13, 1939 2,266,551 Harvey Dec. 16, 1941 FOREIGN PATENTS Number Country Date 154,080 Great Britain Nov. r25, 1920 Great Britain Nov. 23, 1934 OTHER REFERENCES Marks Mech. Eng. Handbook, 4th edition, pp.

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